Elevator systems



Jam 1957 H. CuSAVlNO ET AL 2,776,731

ELEVATOR SYSTEMS Filed March 31, 1954 v 7 Sheets-Sheet 2 Jan. 8, 1957 H. c. SAVINO ET AL ELEVATOR SYSTEMS 7 Sheets-Sheet 3 Filed March 31, 1954 m IImQ m m n nw x I I w z 1' I Ame IIIII I E 5 hohlII I I I I Elan BM om I RO m 2 I I mn wzv 2 2v t l I I I I I I I I I m; 8| I I I I I I J3 oo I I I I I I I I I I I I I I I uz 0+ I TOU 73% Q I I 39 M E S B... .m w I d 3 m F QI I a H gun mo e w i. l I i 6 U Jan. 8, 1957 Filed March 31. 1954 H. C. SAVINO ET AL ELEVATOR SYSTEMS 7 Sheets-Sheet 6 Jan. 8, 1957 H. c. SAVINO ET AL ELEVATOR SYSTEMS 7 Sheets-Sheet 7 Filed March 31, 1954 3 A JIIQW um 2 N2 M2 vz 21L 9 v MPON P2 6 am 8 mN ml 6. N2 9 3 m. llll g ov sf 8 g m 3 w a aw sf e Fig.4A.

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United States Patent ELEVATOR SYSTEMS Henry C. Savino, Hackensack, and Phillip C. Keiper, Shrewsbury, N. J., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa, a corporation of Pennsylvania Application March 31, 1954, Serial No. 419,987

11 Claims. (Cl. 187-29) This invention relates to elevator systems and it has particular relation to elevator systems which are designed for operation without car attendants.

Although aspects of the invention may be employed in elevator systems having car attendants, the invention is particularly desirable for elevator systems of the automatic type which do not have car attendants. For this reason, the invention will be discussed with particular reference to such operatorless systems.

When an elevator car in an operatorless system stops at a landing, such as a floor of a building or structure, it is the practice to hold the elevator car at the floor for a substantial time with its doors open in order to permit loading and unloading of the elevator car. This time is referred to as a non-interference time. In the prior art systems, the non-interference time may be of the order of or more seconds for each stop. if a dispatcher is employed at a terminal landing or floor, the non-interference time may be provided to permit unloading of the elevator car at the terminal floor.

In accordance with the invention, the non-interference time is varied in accordance with the requirements for each of the floors at which a stop is made. To this end, the elevator system is designed to hold an elevator car at a floor at which the elevator stops for a non-interference substantial time, such as 5 seconds. However, if the elevator car is lightly loaded, the non-interference time is reduced. The variation of non-interference time with load is particularly desirable at a terminal fioor if the elevator car doors are to close at the expiration of the non-interference time and to remain closed until the elevator car is selected by the dispatcher as the next car to leave the terminal floor.

If a long non-interference time is desirable at a floor, such as a terminal floor, the invention contemplates the assignment of the increased time only to an elevator requiring such long time. Thus an elevator car approaching a terminal floor is given a long non-interference time only if the elevator car is assigned to be the next car to leave.

It is, therefore, an object of the invention to provide an improved elevator system having a minimum of noninterference time at each elevator car stop.

it is a further object of the invention to provide an elevator system wherein an elevator car is held at one of its stops for a substantial non-interference time and wherein the non-interference time is varied as a function of the loading of the elevator car.

It is also an object of the invention to provide an elevator system wherein an elevator car is held at an elevator car stop with its doors open for a substantial noninterference time only if the elevator car is assigned to be the next elevator car to leave the stop.

Other objects of the invention will be apparent from ice the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 is a schematic view with parts in elevation and parts broken away of an elevator system which may embody the invention;

Fig. 1A is a view in section showing an elevator car employed in Fig. 1 associated with a hoistway;

Figs. 2, 3 and 4 are schematic views including circuits in straight-line form of a control system embodying the invention;

Figs. 2A, 3A and 4A are key representations of electromagnetic relays and switches employed in the circuits of Figs. 2, 3 and 4. If Figs. 2, 3 and 4 are horizontally aligned respectively with Figs. 2A, 3A and 4A, it will be found that coils and contacts of the switches and relays appearing in the key representations are horizontally aligned with the corresponding coils and contacts shown in these circuits.

Figs. 5 and 6 are schematic views in straight line form showing control circuits which embody the invention; and

Figs' 5A and 6A are key representations of electromagnetic relays and switches employed in the circuits of Figs. 5 and 6, respectively.

Although the invention may be incorporated in an elevator system employing various numbers of elevator cars serving buildings or structures having various numbers of floors, the invention can be described adequately with reference to an elevator system having four elevator cars serving a building having five floors. The elevator cars may be dispatched from any desired floors. The elevator cars will be assumed to be dispatched from the first floor and the upper terminal or fifth floor.

Because of the complexity of such systems, certain conventions have been adopted. The elevator cars will be identified by the reference characters A, B, C and D. Since the circuits for the cars are similar, substantially complete circuits are shown for the cars A and B. Components associated with the cars C and D are discussed only as required.

Components associated with the elevator cars B, C and D which correspond to a component of the elevator car A are identified by the same reference character employed for the component of the elevator car A preceded by the letters B, C and D, respectively. For example, the reference characters U, BU, CU and DU designate up switches, respectively, for the elevator cars A, B, C and D. The discussion will be directed primarily to the apparatus and circuits for the elevator car A.

The various relays and switches employed in the circuits may have break or back contacts which are closed when the relay is deenergized and dropped out. The break contacts are open when the relays or switches are energized and picked up.

The relays and switches also may have front or make contacts which are opened when the switches and relays are deenergized and dropped out. These contacts are closed when the switches and relays are energized and picked up. In the drawings the various switches and relays are shown in so far as possible in their tic-energized and dropped-out conditions.

Each set of the contacts associated with a relay or switch is identified by the reference character associated with the relay or switch followed by a numeral identifying the specific set of contacts. Thus, the reference characters U1, U2 and U3 designate, respectively, the first, second and third sets of contacts of the up switch U.

In order to facilitate the presentation of the invention, the apparatus shown in the figures will be briefly set forth,

" d the operation of the complete system thereafter will e discussed. The system includes in part the following s aratus:

APPARATUS SPECIFIC TO CAR A APPARATUS COMMON TO ALL CARS 2BR to 5DR-down floor-call storing relays ZUR to 4UR-up fioor-call storing relays Figure 1 Pi". 1 illustrates the structural relationships of the elevator cars A, B and associated apparatus with reference to the building structure which the elevator cars are intended to serve.

The elevator car A and a counterweight are secured to opposite ends of a rope or cable 11 which passes over a sheave 13. The sheave 13 is mounted on the shaft 14 of an elevator driving motor 15. The shaft 14 also carries a brake drum 16 with which a brake 17 of the conventional spring-applied electrically-released type is associated. The motor is secured to the floor 18 of a penthouse located in the structure which the elevator car is intended to serve.

In order to simplify the association of control circuits with the elevator car A, a control device 19 is provided which is operated in accordance with a function of the movement of the elevator car A. in the specific embodiment of Fig. l, the control device takes the form of a door selector which includes an insulating panel 20 and a brush carriage 21. A screw 22 is mounted for rotation relative to the panel 29. This screw conveniently may be coupled through suitable gearing to the shaft 14 for rotation in accordance with movement of the elevator car A.

The brush carriage 2!. is in threaded engagement with the screw 22. As the elevator car A moves upwardly, the brush carriage 21 is moved upwardly but at a rate much slower than the rate of movement of the elevator car. Similarly, when the elevator car A moves downwardly, the brush carriage 21 also moves downwardly at a slower rate.

The panel 20 carries a plurality of contact segments which are insulated from each other. Thus, the contact segments a2 to (:5 are arranged in a row on the panel 2t"). As the elevator car proceeds upwardly from the basement, :1 crush 23 mounted on the carriage 21 successively engages the contact segments a2 to a5, as the elevator car approaches respectively the floors 2 to 5 of the structure. it will be understood that the contact segments a2 to a5 are spaced from each other in accordance with the spacings of the floors. As will be pointed out below, these contact segments are employed with circuits controlling the stopping of the elevator car during up travel in response to car calls.

As a further example, the panel 20 has a single contact segment e1 which is engaged by a brush 24 mounted on the carriage 21 only when the elevator car A is adjacent the first or dispatching floor. As will be pointed out below, this contact segment is employed in controlling the operation of a dispatching device.

It will be understood that a number of rows of contact segments and a number of brushes may be employed in the floor selector. However, the foregoing discussion is believed sufiicient to illustrate the mechanical relationships of these contact segments and brushes.

Certain apparatus is mounted on or in the elevator car A. Thus, car-call buttons 2c to 4c are provided for registering car calls for the second, third and fourth floors,

espeetively.

A slowdown inductor relay E is provided for the pun pose of initiating a slowdown of the elevator car A as it approaches a floor at which it is to stop. The inductor relay may be of conventional construction and includes two sets of break contacts E1 and E2. When the coil of the inductor relay E is energized, the contacts remain in the positions illustrated in Fig. 1 until the relay is adjacent an inductor plate located in the hoistway of the elevator car A. For example, when the coil of the inductor relay E is energized and the inductor relay is adjacent the magnetic plate UEP for the second floor, the magnetic circuit is completed, which results in opening of the break contacts E1. When open, the contacts remain open until the coil of the inductor relay E is deenergizcd. The inductor plate UEP is positioned to be reached by the inductor relay E as the elevator car approaches the second floor for the purpose of initiating slowdown of the elevator car. It will be understood that a similar inductor plate is similarly associated with each of the fioors at which the elevator car is required to stop during up travel.

If the coil or" the inductor relay E is energized during down travel of the elevator car, and it the relay reaches the inductor plate DEE for the second floor, a magnetic circuit is completed which results in opening of the break contacts E2. When opened, the contacts remain open until the coil is deenergized. The inductor plate BB? is so positioned that it initiates solwdown of the elevator car A a suitable distance from the second floor. A similar inductor plate would be similarly associated with each of the lloors at which the elevator car A is to stop during down travel.

The elevator car A also carries a stopping inductor rclay F which is similar in construction to the inductor relay E. This relay is employed for initiating a s 1. operation of the elevator car A. The stopping iutlue relay F cooperates with inductor plates UP? and in a manner which will be clear iron: the discussion of the cooperation of the slowdown inductor relay with the inductor plates UEP and DEF. if the coil of the relay F is energized and if the elevator car is to stop at the second floor while traveling up, when the inductor relay F reaches the inductor plate UP? a magnetic circuit is completed which results in opening of the break contacts F1. This initiates a stopping operation or the elevator car. An inductor plate similar to the plate UP? is similarly associated with each of the floors at which the elevator car A is to stop during up travel thereof. it the elevator car A during down travel is to stop at the second floor, the coil of the stopping inductor relay F is energized, and when the inductor relay reaches the inductor plate DFP for the second fioor, a magnetic cuit is completed which results in opening of the contacts P2. This initiates a stopping operation of the elevator car A. It will be understood that an inductor plate similar to the inductor plate DP? is similarly associated with each of the floors at which the elevator A is to step during down travel thereof.

The elevator car A also carries a cam 26 which is positioned to operate a mechanical switch 63 located in the hoistway associated with the elevator car. The mechanical switch 63 normally is closed and is opened by the cam 26 when the elevator car A is adjacent the first or dispatching floor. It will be understood that other mechanical switches may be operated in a similar manner by the elevator car A.

An intending passenger on the fourth floor may register a 'floor call for elevator car service in 'the up direction by pressing a button of a push-button switch 4U. A similar push-button switch is located at each of the intermediate floors from which an intending passenger may desire to proceed in'an up direction.

If the intending passenger at the fourth floor desires to proceed in a down direction, he may press the button of a push-button switch 4D located at the fourth floor. A similar push-button switch is located at each of the intermediate floors from which an intending passenger may desire to proceed in a down direction.

The elevator car A is provided with a door D? which is mounted to slide across the passage through which passen'ge'rs enter and leave the elevator car. The door is moved by means of a lever 28 which is pivotally mounted on the car by means of a pivot 28A. The lever 28 is moved in a clockwise direction about a pivot by means of a door-close solenoid DC for the purpose of closing the passage and is moved in a counterclockwise movement about its passage to open the door by means of a door-open solenoid DO.

It will be understood that a separate hoistway door DPH (illustrated in Fig. 1A for the elevator car A) is provided for each of the floors served by the elevator car. The coupling of the two doors may be efr'ect'ed in a conventional manner as by a vane DPV which is secured to the door DP for reception in the slot of 'a. slotted bloc-k DPB which is mounted on the hoistway door DPH. The hoi's'tway door DPH is moved to close and expose a hoistway passage through which load enters and leaves the elevator car.

If desired, the edge of the door DP which is the leading edge during a door-closing movement may be a safetyedge of conventional type. As well known in the art, when such an edge reaches an obstruction, it operates a switch to stop or reopen the door. In the embodiment of the invention now being discussed, it will be assumed that such an edge is not employed.

A suitable load-responsive device is provided for controlling circuits in accordance with elevator car load. Thus, a spring-mounted plat-form PL closes a normally open switch PLl when the elevator car carries a light load such as two or more persons. The platform closes normally-open contacts PLZ-l and PL22 of a switch PL2 when the elevator car carries a substantial load such as 80% of rated capacity.

Figure 2 Fig. 2 shows circuits for the driving motor, the brake, the speed relay V, the up switch U, the down switch D, the car-running relay M, the holding relay G, the slowdown inductor relay E, the stopping inductor relay F, the up-preference relay W, the down-preference relay X, the timing relay 701", the door relay 40, the door-control relay 45, the door-close relay DC, and the door-open relay D'O. Energy for the various circuits is derived from direct-current buses L+ and L.

Although various motor control circuits may be employed, itwill be assumed that a control circuit of the variable-voltage type is empioyed. By inspection of Fig. 2, it will be noted that the armature 15A of the driving motor 15 and the armature 29A of a direct-current generator 29, together with a series field winding 2913 for the generator, are connected in a series or loop circuit. The field winding 15B for the driving motor 15 is connected directly across the buses L+ and L-.

The magnitude and direction of energization of the driving motor 15 are controlled by the direction and magnitude of the energization of a separately-excited field winding 29C provided for the generator 29. It will be understood that the armature 29A of the generator is rotated at a substantially constant rate by a suitable motor (not shown).

When the elevator car A is conditioned for up travel, the generator field Winding 29C is connected across the buses L+, L-- through make contacts U2 and U3 of the up switch. When the elevator car A is conditioned for down travel, the generator field winding 29C is connected across the buses through the make contacts D2 and -D3 of the down switch. The energizing circuit for the field winding may include a resistor R1 which is shunted by make contacts V1 of the speed relay V. By inspection of Fig. 2, it will be observed that the contacts U2, U3, D2 and D3 constitute in effect a reversing switch for controlling the direction of energization of the field winding. The resistors R1 and the contacts V1 are provided for controlling the magnitude of energization of the field winding.

The speed relay V may be energized through either of two circuits. One of the circuits includes make contac'ts U4 of the up switch U, a limit switch 30 which is normally closed and which is opened as the elevator car A nears the upper limit of its travel and the break contacts E1 of the slowdown inductor relay E. The other circuit is completed through make contacts D4 of the down switch D, mechanical limit switch 31 which is normally closed and which is opened as the elevator car nears the lower limit of its travel in the down direction, and break contacts E2 of the slowdown inductor relay.

As previously pointed out, the brake 17 normally is spring-biased into engagement with the brake drum 16 and is released by energization of a brake coil 17B. The coil may be energized either through make contacts U1 of the up switch U or through make contacts D1 of the down switch D.

In order to energize the car-running relay M, certain safety devices 33 must be in their safe conditions. Such safety devices may include switches which are open when the doors of the elevator car and the associated hoistway doors are open, and which are closed when the doors are closed to control the door relay 40. Such safety devices arewell known in the art. The car-running relay M may be energized through either of two circuits. One of the circuits includes the make contacts -1 of the starting relay 80, make contacts W1 of the up-pr'efe'rence relay W, break contacts P1 of the stoppinginductor relay, normally-closed contacts of a mechanical limit switch 34 which are opened when the car nears the upper limit of its travel, and the coil of the up switch U. When energized, the up switch U closes its make contacts US to complete a holding circuit around the contacts 80-1 and W1.

The second circuit for energizing the car-running relay M includes the contacts 80-1 of the starting relay, make contacts XI of the down-preference relay X, break contac'ts F2 of the inductor stopping relay, normally-closed contacts of a mechanical limit switch 35 which are opened as the elevator car nears the lower limit of its travel in the down direction and the coil ofthe down switch D. When the down switch D is energized, make contacts D5 are closed to provide a holding circuit around the contacts 80-1 and X1.

. Before the holding relay G and the inductor relays E and F can be energized, make contacts M1 of the car-running relay must be closed. In addition, any one set of make contacts TTl of the car-call stopping relay, and K1 of the floor-call stopping relay must be energized. A holding circuit around these contacts is established upon closure of the make contacts G1. Energization of the inductor stopping relay F further requires closure of the break contacts V2 of the speed relay.

The up-prefer'ence relay W is energized only if the elevator car is not operating in the down direction (break contacts D6 are closed); the elevator car is not conditioned for down travel (break contacts X2 are closed); and normally-closed contacts of a mechanical limit switch 36 are closed. The mechanical limit switch 36 is opened as the elevator car reaches its upper limit of travel.

Energization of the down-preference relay X requires closure of the break contacts U6 of the up switch, closure of the break contacts W2 of the tip-preference relay, and closure of the normally-closed contacts of a mechanical limit switch 37. The mechanical limit switch 37 is open when the elevator car A is adjacent the first or dispatching lloor.

The doors for the elevator car A are controlled by a door-control relay 45. For this relay to be initially energized, the break contacts N1 and TNI must be closed to indicate that the elevator car is not being loaded at a terminal floor. In addition, the break contacts 7011 must be closed to indicate that the noninterference time has expired. When the relay 45 picks up, it closes make contacts 451 to partially complete a holding circuit for the relay.

The door-control relay 45 controls the energization of the door-close solenoid DC and the door-open solenoid DO. If the contacts 45-2 of the door-control relay are closed, and the break contacts 40-2 are closed, the solenoid DC is energized. The contacts 40-2 are closed when the door of the elevator car A or an associated hoistway door is away from its closed condition.

If the door-control relay 45 is dropped out, the make contacts 45-3 are closed to complete with the switch 38 an energizing circuit for the door-open solenoid DO. The switch 38 is a limit switch which is normally closed and which is opened as the door reaches its fully-open position.

Circuits for controlling the timing relay 70T are enclosed in a broken-line rectangle RE. The timing relay 70T is connected for energization by make contacts MS of the car-running relay or by make contacts DO-l of the door open relay. It will be noted that a resistor R2 and a capacitor CA1 in series are connected across the timing relay 70T. If the timing relay is energized and the contacts M and D01 both thereafter open, the capacitor CA1 discharges through the relay 701 to delay the dropout of the timing relay 70T for a suitable noninterference time, such as 3 seconds.

If the elevator car is at a predetermined floor, in this case the lower terminal floor, the make contacts L3 are closed. If the elevator car carries say two passengers to be unloaded switch PLl is closed to connect the resistor R3 and the capacitor CA2 through the contacts L3 acros the relay 70'1". When the contacts DO-l and M5 both open the capacitors CA1 and CA2 discharge to delay dropout of the relay 701 for say 4 seconds. If the elevator car has a full load to be discharged the switch contacts PL21 are also closed and the three capacitors CA1. CA2 and CA3 all are etfective to delay dropout of the relay 70T for say 5 seconds.

Figure 3 Fig. 3 illustrates circuits for energizing the car-call stopping relay TT, the floor-call stopping relay K and the main starting relay 80.

The car-call push buttons 20 to 4c normally are biased into their open positions. Each of the push buttons is provided with a holding coil Zcc to 40, which is effective for holding the associated push button in its operated condition following a manual operation of such push button. To this end, the push buttons may be made of magnetic material. Such construction of the push buttons is well known in the art.

Each of the push buttons 20 to 40 controls the connection of contact segments to the bus L+. Thus, when operated, the push botton 20 connects the contact segment hl to the bos L+. When operated, the push button 20 connects the contact segments a2 and I12 to the bus L+. The push buttons 3c and 4c similarly connect contact segments for the third and fourth floors to the bus L+. Inasmuch as the elevator car is assumed to stop at the fifth floor or upper terminal floor at all times during up travel, the contact segment a5 is permanently connecten to the bus L+. Similarly, during down travel, the elevator car A always stops when it reaches the first floor, and the contact segment hl for the first floor is permanently connected to the bus L+.

it will be understood that the contact segments a2 to n5 are arranged in a row on the floor selector 19 of Fig. l and are successively engaged by a brush 23 as the elevator car moves from its lower limit to its upper limit of travel. In a similar manner, the contact segments I14 to 111 are arranged in a row in the order of the floors tor successive engagement by a brush as the elevator car moves from the upper terminal to its lower limit of travel.

During up travel of the elevator car A, the car-call stopping relay TT is connected between the brush 23 and the bus L through make contacts W3 of the up-preference relay and make contacts M3 of the car-running relay. Consequently, when the brush 23 reaches one of the contact segments [:2 to (:5 which is connected to the bus L+, the car-call stopping relay TT is connected for energization across the buses L+ and L- for the purpose of stopping the elevator car at the next floor reached by the car. As the elevator car stops, the brush 23 preferably passes slightly beyond the associated contact segment.

When the elevator car A is conditioned for down travel, the car-call stopping relay TT is connected between the crush 40 and the bus L through the make contacts X3 of the down-preference relay and the make contacts M3 of the car-running relay. Consequently, when the brush 40 reaches one of the contact segments k4 to 111 which is connected to the bus L+, the car-call stopping relay TT is energized to initiate a stopping operation of the elevator car at the next floor reached by the car. As the elevator car stops, the brush 40 preferably passes slightly beyond the associated contact segment.

The coils 2cc to 4cc are connected in series for energization either through make contacts W4 of the uppreference relay or make contacts X4 of the down-pref erence relay. When the elevator car reverses its direction of travel, the make contacts W4 and X4 both are momentarily opened to deenergize the associated holding coils for the purpose of resetting the car-call push buttons.

When the down lloor-call push button 2D is operated, the down floor-call storing relay ZDR is connected therethrough across the buses L+ and L- for energization. Upon energization, the relay closes its make contacts 2DR1 to establish a holding circuit around the push button. The contact segment f2 now is connected (and corresponding contact segments for the remaining elevator cars are connected) through the contacts 2DR1 to the bus L+. The contact segments f4 and f3 similarly are connected to the bus L+ by operation of the down floor-call push buttons 4D and 3D. The contact seg ments f4, f3 and f2 for the fourth, third, and second floors are positioned in a row on the floor selector 19 of Fig. l for successive engagement by a brush 58 as the elevator car A moves from the upper terminal in a down direction.

The floor-call stopping relay K is connected between the bus L+ and the brush 58 through make contacts X5 of the down-preference relay. Consequently, if the elevator car A approaches the second floor during a down trip while a down fioor call is registered for such floor. the engagement of the contact segment f2 by the brush 58 completes an energizing circuit for the floor-call stopping relay K.

Each of the down floor-call storing relays 4DR, 3DR and 2BR has an operating coil and a cancelling coil. respectively, iDRN, 3DRN and ZDRN which is energized in opposition to the energization of the operating coil. The cancelling coil ZDRN is connected between a contact segment g2 (and similar contact segments BgZ etc. for the other elevator cars) and the bus L+ through the make contacts 2DR1. As the elevator car A reaches the second floor, the following energizing circuit for the cancelling coil is established:

L+, 2on1, ZDRN, g2, 59, X6, M4, L-

Energization of the coil ZDRN opposes energization of the relay by the operating coil and resets the relay. It will be understood that the contact segments g4, g3 and g2 are arranged in a row for successive engagement by the brush 59 as the elevator car proceeds downwardly from the upper terminal floor to control the energization of the cancelling coils 4DRN, SDRN and ZDRN.

The down floor-call storing relays all cooperate with the brushes 58 and 59 in substantially the same manner to control the energization of the floor-call stopping relay during down travel of the elevator car.

When the up floor-call push button 2U is operated, the up floor-call storing relay 2UR is connected for energization therethrough across the buses L+ and L-. Upon operation, the relay closes its make contacts 2UR1 to establish a holding circuit around the push button 2U. As a result, a contact segment b2 is connected (and contact segments Bb2 etc. for the other elevator cars are connected) to the bus L+ through such make contacts.

As the elevator car during up travel approaches the second fioor, the brush 60 engages the contact segment [22 to establish the following energizing circuit for. the floor-call stopping relay:

This conditions the elevator to stop at the second floor. As the elevator car stops at the second floor, a brush 61 engages the contact segment c2 to establish the following circuit for the cancelling coil of the storing relay ZUR:

L+, 2UR1, ZURN, c2, 61, W6, M4, L-

Such energization of the cancelling coil results in resetting of the storing relay which has its main coil acting in opposion to the cancelling coil. The up floor-call push but tons 3U and 4U similarly control the associated storing relays and contact segments. It will be understood that the contact segments 02, c3 and c4, and contact segments b2, b3 and b4 are arranged in rows on the floor selector for engagement successively by the brushes 61 and 60, as the elevator car A proceeds upwardly.

The starting relay 80 can be energized only if the timing relay 70T is decncrgized and dropped out to close its break contacts 70T2 when the elevator car is positioned at the lower dispatching floor, the energizing circuit for the starting relay normally is completed through the make contacts S1 of an auxiliary starting relay. At the upper terminal or dispatching floor, make contacts T51 may operate in a manner similar to the operation of the contacts S1 for the lower dispatching floor to start the elevator car from the upper terminal floor. Between the dispatching floors, the make contacts S1 are shunted by the contacts of a mechanical switch 63. This switch is cam operated to open when the elevator car is adjacent the upper terminal or dispatching floor and the lower dispatching floor. For all other positions of the elevator car A, the switch 63 is closed.

It dispatchers at the terminal floors are not required, a switch 63A may be manually closed to shunt the switch 63.

Figure 4 in Fig. 4, a dispatching device is illustrated which normally controls the lower terminal dispatching of the elevator cars employed in the system.

The selection and timing mechanism include as one component a motor 71 which operates substantially at constant speed. This motor may be of any suitable type, but for present purposes it will be assumed that the motor is a squirrel-cage alternating-current motor which is energized from a suitable .source of alternating current. The motor 71 is connected through a spring-released electromagnetically-applied clutch 72 to a cam 73 having a protuberance for successively operating mechanical switches Y, BY, CY and DY which are associated with the respective elevator cars. The electromagnetic clutch can be energized only if one or more elevator cars are located at the dispatching floor which is assumed to be the first floor (one or more of the contacts L1, BLl, CLl, DL1 are closed), and if no elevator car has been selected as the next car to leave the dispatching floor (break contacts N2, BN2, CN2, and DN2 all are closed).

The motor 71 also may be coupled through a springreleased electromagnetically-applied clutch 74 to a cam 75 which is biased towards a predetermined position by a spring 76. The cam 75, when coupled to the motor 71, is rotated against the bias of the spring to close normally-open contacts 77 a predetermined time after the cam 75 is coupled to the motor 71. The clutch 74 can be electrically energized only if no elevator car is being started (break contacts S2, BS2, CS2 and D52 are closed), and if the break contacts 181 of the holding relay 18 are closed. The holding relay 18 is energized upon closure of the contacts '77 to close its make contacts 182 for the purpose of establishing a holding circuit around the contacts 77.

The presence of an elevator car at the dispatching floor is determined by the energization of a car-position relay for each of the elevator cars. Thus, a car-position relay L for the elevator car A is energized when the brush 24 engages. the contact segment e1.

The brush 24 is operated by the floor selector for the elevator car A to engage the contact segment e1 when the elevator car is at the dispatching floor.

If the elevator car A is at the dispatching floor (make contacts L2 are closed), if it has been selected as the next car to leave the dispatching floor (switch Y is closed), and if it is not being started (break contacts S3 are closed), the loading relay N for the elevator car A is energized. The loading relay may be employed in a conventional way to permit loading of the elevator car A. For example, the loading relay when energized may operate a loading signal, such as a lamp, which indicates that passengers may enter the elevator car. Conveniently, the loading relay N when energized opens the normallyclosed doors of the elevator car A to permit entry of passengers into the elevator car.

After the expiration of a time sufiicient for cam 75 to close the contacts 77 and energize the relay IS, the make contacts 183 close to complete the following circuit:

L+, L2, S, N3, 183, L-

The relay S when energized closes its make contacts S4 to establish a holding circuit around the contacts N3 and 183, and starts the elevator car A from the dispatching floor.

If it is desired to expedite the dispatch of a loaded car, the expeditor relay 28 may be energized through a parallel circuit having one arm for each of the elevator cars. The arm for the elevator car A has in series break contacts 70T3 of the timing relay 701, contacts PLZ-Z of the load-responsive switch PLZ and make contacts N4 of the loading relay N. Thus if the elevator car A is selected as the next car to leave the lower terminal floor (contacts N4 are closed) if it is loaded (switch PL2-2 is closed) and if the non-interference time has expired (contacts 70T3 are closed), the relay 28 picks up to expedite the dispatch of the car.

OPERATION In order to explain the over-all operation of the elevator system, it will be assumed first that the elevator cars are at the first or dispatching floor when the system initially Whereas break contacts W2 of the relay are open. Switch 81 (Fig. 2) is assumed to be open.

The switch 63A (Fig. 3) is assumed to be open. Since the cars are at the first floor, the switch 63 is open. The timing relay 70T is assumed to have timed out. The relays 45 and 40 are picked up and the elevator car doors are closed.

The motor 71 (Fig. 4) is energized to rotate at a substantially constant rate.

Inasmuch as the elevator cars are assumed to be at the dispatching floor, the car-position relays L, etc. energized.

As a result of its energization, the car-position relay L closes its make contacts L2 to prepare certain circuits or subsequent energization. In addition, the make contacts L1 close to complete the following circuit for the clutch 72.

L+, L1, 72, N2, BN2, CNZ, BN2, L

The clutch now couples the motor 71 to the cam 73 for the purpose of successively closing and opening the associated mechanical switches. It will he assumed that the first switch reached by the cam is the switch Y for the elevator car A. Closure of this switch completes the following energizing circuit for the loading relay of the elevator car A:

L+, L2, N, S3, Y, L-

The loading relay N upon energization initiates opening of normally-closed doors of the elevator car A to permit intending passengers on the dispatching floor to enter the elevator car. Such opening is effected by opening of contacts N1 (Fig. 2) to deenergize the door-control relay 45. This relay opens its contacts 45-1 and 45-2 without immediate effect on system operation. However, closure of contacts 45-3 energizes the solenoid D to open the doors. The solenoid DO also closes its contacts D01 to energize the timing relay 70T, and the relay 70T opens its break contacts 70T1 and 70T2 without immediate effeet on the systems.

In opening, the door opens its set of contacts 33 to deenergize the door relay 40 which opens its contacts 40-1 and closes its contacts 40-2 without immediate effect on system operation. When it reaches open position, the door opens limit switch 38 to deenergize the solenoid DO. The solenoid DO opens its contacts D01 to initiate a timing out operation of the timing relay 70T.

Opening of the break contacts N2 (Fig. 4) deenergizes the clutch 72. Consequently, the cam 73 is uncoupled from the motor 71. Finally, the make contacts N3 close to prepare the starting relay S for subsequent energization. Closure of make contacts N4 has no immediate effect on the operation of the system.

Upon expiration of its timing period the relay 7%? drops out to close its break contacts 7911, 78T2 and 70T3. Such closures prepare circuits for subsequent operation.

When the system was placed in operation, the clutch 74 was energized through the circuit:

L-}-, 181, 74, S2, BS2, CS2, D52, L-

As a result of its coupling to the motor 71, the cam 75 rotates against the bias of its spring 76 until at the expiration of the time interval allowed for leading elevator cars the contacts 77 close. Closure of these contacts completes the following circuit:

L+, IS, 77, S2, BS2, CS2, D52, L-

The energized relay 1S closes its make contacts 152 to establish a holding circuit around the contacts 77. The break contacts 181 open to denergize the clutch l4, and the spring 76 now rotates the cam to its starting position.

' for the door-closing relay 45.

Also, the make contacts 183 close to energize the auxiliary starting relay S through the following circuit:

L+, L2, S, N3, 183, L-

Energization of the auxiliary starting relay S closes the make contacts S4 to establish a holding circuit around the contacts N3 and 183. Break contacts S3 open to deenergize the loading relay N. Break contacts S2 open, and this opening causes relay 15 to drop out. This has no immediate eifect on the system operation.

The loading relay when denergized opens its make contacts N3 and N4 without immediate effect on the operation of the system. In addition, break contacts N2 close to prepare the clutch 72 for subsequent energization.

The deenergization of the loading relay further closes break contacts N1 (Fig. 2) to complete with the contacts 70Tli an energizing circuit for the door-control relay 45. The latter relay closes it make contacts -1 and opens its break contacts 45-3 without immediate effect on system operation. However, closure of make contacts 45-2 completes with the contacts 40-2 an energizing circuit for the door-close solenoid DC, and the door now starts to close.

Upon closing, the door closes its switch 33 to complete an energizing circuit for the door relay 4-0 which closes its make contacts 40-1 and opens its break contacts 40-2 to deenergize the door-close solenoid DC.

Turning now to Fig. 3, it will be noted that closure of the make contacts S1 results from energization of the auxiliary starting relay S. Inasmuch as the elevator car A is assumed to have remained at the dispatching floor for a time suflicient to permit closure of the break contacts T2, an energizing circuit now is complete for the main starting relay 80.

The previously mentioned closure of contacts 40-1 of the door relay (Fig. 2) coupled with closure of the make contacts -1 of the starting relay completes the following circuit for the up switch and the car-running relay:

L+, S0-1,W1, Fl, 34, U, M, 40-1, L-

The energized up switch U closes its make contact U1 to release the brake 17, and contacts U2 and U3 close to energize the generator field winding 29C with proper polarity for up travel of the elevator car. Make contacts U4 close to complete through the limit switch 30 and the contacts E1 an energizing circuit for the speed relay The speed relay closes its make contact V1 to shunt the resistor R1 and condition the elevator car A for full speed operation in the up direction. Also, the speed relay opens its break contacts V2 to prevent energization therethrough of the stopping inductor relay F.

Returning to the up switch U, it will be noted that closure of the make contacts U5 establishes a holding circuit around the contacts 8-0-1 and W2. Gpening of the break contacts U6 prevents energization therethrough of the down preference relay. The elevator car A new is in condition for full speed operation in the up direction and departs from the dispatching floor.

It will be recalled that the car-running relay M was energized with the up switch U. The car-running relay closed its make contacts M1, M3 and M4 (Fig. 3) without immediate efiect on the operation of the system. However, closure of the make contacts M2 (Fig. 2) com pletes with the contacts 45-1 and N1 21 holding circuit Closure of the make contacts M5 energizes the timing relay 7ST. This relay opens its break contacts 76T2 (Fig. 3) which causes the starting relay 80 to become deenergized. Opening of reak contacts 70T1 (Fig. 2) and 70T3 (Fig. 4) does not immediately atfect system operation.

It will be assumed now that the passenger in the elevator car operates the car-call push button 3c (Fig. 2) to register a car call for the third floor. Such operation connects the contact segments a3 and h3 to the bus L+. As the elevator car nears the third floor, the brush 23.

13 engages the contact segment a3 to complete the following circuit for the car-call stopping relay TT:

L+, 30, a3, 23, W3, TT, M3, L-

The car-call stopping relay now closes its make contacts TTI (Fig. 2) to energize the holding relay G and the slow-down inductor relay E through the closed contact-s M1. Energization of the holding relay G completes through the make contacts G1 a holding circuit around the contacts TTI.

When the elevator car A in its upward travel reaches the inductor plate UEP (Fig. 1) for the third floor, the break contacts B1 are opened to deenerg-ize the speed relay V (Fig. 2). The speed relay opens its break contacts V1 to introduce the resistor R1 in series with the generator field winding 29C. The resultant reduction in field current slows the elevator car to a landing speed. In addition, the speed relay V closes its break contacts V2 to complete through the contacts Gland M1 and energizing circuit for the stopping inductor relay F.

Shortly before :the elevator car A in its continued upward movement at the landing speed reaches the third door, the inductor plate UFP for the third floor is adjacent the stopping inductor relay and completes amag-netic circuit which results in opening of the contacts =F1. Opening of the contacts F1 (Fig. 2) deenergizes the up switch U and the tear-running relay The up switch U opens its make contacts U1 to deenergize the brake 17., and the brake is promptly forced against the brake drum 16 by its associated spring. :Con- 'tacts U2 and U3 open :to deenergize the generator field Winding 29C. Consequently, the elevator .car A stops accurately at the third floor. Opening of the make contacts U4 and U5 and closure of the break contacts U6 have no immediate xeflfect on the :operation of the system. As the elevator car comes to a stop the brush 23 may pass the .contact segment for .-a slight distance to .deenergize the relay TT.

The previously-mentioned deenergization of the .carrunning relay resulted in opening of the make .contacts M1 to .deenergize the inductor relays E and F and the holding relay G. The holding relay G opened its make contacts G1 without immediately affecting the operation of the system.

The car-running relay also opened its make contacts M5 to start a timing-out operation .Of the timing relay 701. This relay has a time delay in -,drop out suflicient to permit discharge of passengers .or entry of passengers into the elevator car A. For example, a time delay of .three seconds may be employed. Opening of the make contacts M3 and closure of the break contacts M4 have no immediate effect on the operation .of the system.

Opening of make contacts M2 deenergizes the door control relay 45 and this relay opens its make contacts 45-1 and 45-2 without immediate :effect on system "operation. However, closure of break contacts 45-3 completes with the switch 38 .a circuit for the door-open solenoid DOand the door now opens. Thesolenoid DO also closes itscontacts D01 to reenergize the timing relay 7tlT. However when the door reaches its pen position the switch 38 opens todeenergize :the solenoid ,DO and the contacts D01 open to permitthe timing relay to time .out. In opening, the dooropens its switch 33 to deenergize the door relay40 without-immediate efiect on system operation.

Let it be assumed that tinstead-of a car call, an 'up floor call was registered for the third floor by operation of the push button 3U .(Fig. 3). Such operation energizes the up floor call storing relay EUR which closes its make contacts 3UR1 to establish a holding circuit around the push button. The contacts ,3UR1 also serve to connect the control segment b3 and corresponding contact segmentsfor the remaining elevator .cars of the system to the bus L+.

As the elevator car approaches the third floor, the

1'4 brush 60 engages the contact segment [23 to energize the floor-call stopping relay K through the following circuit:

L+, 3UR1, b3, 60, W5, K, L-

Upon energization, the floor call stopping relay closes its make contacts K1 (Fig. 2) to energize through the contacts M1 the holding relay G and the slowdown inductor relay E. These relays operate in the same manner previously discussed to stop the elevator car accurately at the third floor.

As the elevator car A slows down to stop at the third floor, the brush 61 engages the contact segment 03 to complete the following cancelling circuit:

L+, 3UR1, 3URN, c3, 61, W6, M4, L

It will be recalled that the break contacts M4 close as the elevator car stops at the third floor. As a result of its energizat'ion, the cancelling coil SURN resets the up floor-call storing relay for the third floor.

Referring to Fig. 3, it will be recalled that the mecham ical switch 63 is closed only at the dispatching-floor and the upper-tenninal-fioor positions of the elevator car. .Since the elevator car is now at the third floor, the switch 63 is closed. Consequently, as soon as the timing relay 70T drops out, the break contacts 7tlT2 close to complete an energizing circuit for the starting relay 80. This operates in the manner previously discussed to start the elevator car upwardly. In this way, the elevator car A continues to the upper terminal floor, answering all registered car calls and all registered up floor calls during its upward trip.

As the elevator car A approaches the upper terminal or fifth fioor, the brush 23 '(Fig. 2) engages the contact segment a5 to complete the following energizing circuit for the car-call stopping relay:

L+,-a5, 23, W3, TT, M3, L-

The car-call stopping relay operates in the manner previously discussed to stop the elevator car accurately at *the upper-terminal floor.

As the elevator car A reaches the upper-terminal floor, the mechanical switch 63 ('Fig. 3) opens. Consequently, the elevator car A cannot start from the upper-terminal floor until it is started by its upper-terminal dispatching device represented by the contacts T S1. It will be understood that the upper-terminal dispatching device may be similar to the dispatching device discussed for the first floor. For present purposes it will be assumed that the contacts TS]. operate for the upper-terminal dispatching floor in the same manner by which the contacts S1 operate for the lower dispatching floor.

As the elevator car reaches the fifth floor, the limit switch 36 '(Fig. 2) opens to deenergize the up-preference relay W. This relay opens its make contacts W1, W3, W5, W6, without immediately affecting the operation of the system. However, opening of the make contactsWd deenergizes the holding coils for the car-call push buttons, and these are reset. In addition, closing of the break contacts W2 completes the following energizing circuit for the down-preference relay:

The down-preference relay X closes its make contacts X l, X3, X4, X5 and X6 and opens its break contacts X2 to .condition the. elevator car for down travel.

it will ,be assumed next that-the dispatching device for the upper terminal floor closes its contacts TSl ('Fig. 3) and that the timing relay has closed its break contacts 7.011 to complete an energizing circuit for the starting relay 80. The loading relay of the dispatching device for the upper-terminal floor operates the contacts TN! to control the'door-control relay 45 in the same manner by which contacts N1 control the door-control relay at the lower terminal floor. The closing of .the doors coupled with the closing of the make contacts 30-1 .com-

' 15 pletes the following circuit for the down switch D and the car-running relay M:

L+, 80-1, X1, F2, 35, D, M, 4&4, L-

The car-running relay M operates in the manner previously described to prepare certain circuits for subsequent operation.

Upon energization, the down switch D closes its make contacts D1 to release the brake 17. In addition, make contacts D2 and D3 close to energize the generator field winding 29C in the proper direction for down travel of the elevator car. Closure of the make contacts D fcompletes an energizing circuit for the speed relay V. This relay closes its make contacts V l to shunt the resistor Rt and opens its break contacts V2. The elevator car now is conditioned for movement in the down direction at full speed and moves away from the upper terminal floor.

Closure of make contacts D5 establishes a holding circuit around the contacts M4 and X1. Opening of break contacts D6 has no immediate efiect on the operation of the system.

It will be understood that as the elevator car leaves the upper terminal door, the limit switch 35 (Fig. 2) and the switch 63 (Pig. 3) reclose.

it will be assumed next that a passenger in the elevator car operates the car-call push button 3c for the purpose of registering a car call for the third floor. This button connects the contact segments (13 and 113 to the bus L+.

When the brush 40 reaches the contact segment 123, an energizing circuit is established for the car-call stopping relay TT as follows:

L+, 3c, I23, 49, X3, TT, M3, L

Consequently. the relay closes its make contacts TTI. to energize through the contacts M1 the holding relay G and the inductor relay E. The holding relay G closes its make contacts G1 to establish a holding circuit around the contacts TT1.

When the slowdown inductor relay E reaches the inductor plate DEP for the third floor (Fig. l), the contacts E2 open to deenergize the speed relay V (Fig. 2). The speed relay opens its make contacts V1 to introduce the resistor R1 in series with the generator field winding 29C. The elevator car now slows to a landing speed in addition, the break contacts V2 close to complete an energizing circuit for the stopping inductor relay F.

When the stopping inductor relay F reaches the inductor plate DP? for the third. floor, the contacts F2 open to deenergize the down switch D and the car-running relay M. The down switch D opens its make contacts D1 to permit reapplication of the brake 37. Make contacts D2 and D3 open to decnergize the generator field winding. and the elevator car A stops accurately at the third floor. Opening of the make contacts D4 and D5 and closing of the break contacts D5 have no immediate effect on the operation of the system. As the elevator car cotnes to a stop the brush 40 may pass the contact segment I13 slightly to deenergizc the relay TT.

The car-running relay M opens its make contacts M1 to deenergize the inductor relays and the holding relay G. The holding relay G in turn opens its make contacts G1 to prevent subsequent energization therethrough of the inductor relays.

The make contacts M2 open to initiate an opening op eration of the doors. The opening and closing of the doors will be understood from the previous discussion thereof.

The car-running relay l/l also opens its make contacts M5 and this is followed by opening of the contacts DO-l to start a timing-out operation of the timing relay 701. Opening of make contacts M3 and M5 and closing of break contacts M4 have no immediate effect on the operation of the system. When the timing relay "itlT drops out, the break contacts 70T2 (Fig. 3) close to energize through the switch 63 the starting relay St). The starting relay 16 operates in the manner previously described to start the elevator car down from the third floor.

Let it be assumed that instead of a car call a down floor call was registered for the third floor by operation of the push button 3D (Fig. 3). Such operation energizes the down floor-call storing relay 3DR which closes its make contact 3DR1 to establish a holding circuit around the push button 3D. The contact segment f3 and corresponding contact segments for the remaining elevator cars of the system are connected through the make contacts 3DR1 .to the bus L+.

As the elevator car A approaches the third floor in the down direction, the brush 58 reaches the contact segment f3 to complete an energizing circuit for the floor call stopping relay K as follows:

L+, 3DR1, f3, 58, X5, K, L

The relay K closes its make contacts K1 (Fig. 2) to energize the holding relay G and the slowdown inductor relay E through the contacts M1. These relays operate in the manner previously described to stop the down traveling elevator car at the third floor.

During the stopping operation, the following cancelling circuit Fi g. 3) is established:

L+, 3DR1, 3DRN, g3, 59, X6, M4, L-

As a result of energization of the cancelling coil SDRN, the down floor call storing relay SDK is reset.

When the elevator car in its down travel nears the first or dispatching floor, the brush 40 (Fig. 2) engages the contact segment ill to complete the following circuit.

L+, hl, 40, X3 TT, M3, L-

The energization of the car-call stopping relay TT stops the elevator car at the first floor in the same manner discussed with reference to the stopping of the elevator car at the third floor.

As the elevator car A stops at the first floor, the mechanical switch 37 opens to deenergize the down-preference relay X. This relay opens its make contacts X X3, X5 and X6 without immediately afiecting the operation of the system. However, closure of the break contacts X2 completes an energizing circuit for the up preference relay W. This operates in the manner previously discussed to condition the elevator car for up travel.

It will be noted that as the relay X is deenergized the make contacts X4 and W4 are open until the up preference relay W is again energized. During this momentary opening of both sets of contacts, the holding coils for the carcall push button are deenergized to reset the buttons.

Next the elfect of the closure of the switches 81 and B81 (Fig. 2) 0n the operation of the system will be considered. It will be recalled that if the elevator car A approaches the lower terminal floor with say, one passenger to be discharged, the non-interference time during which the elevator car door is maintained open is determined by the resistor R2 and the capacitor CA1 connected across the non-interference relay T.

if the non-interference time under these circumstances is of the order of three seconds, it follows that the elevator door recloses reasonably soon after the passenger is discharged. For this reason if the elevator car A is not selected as the next car to leave the lower terminal floor, intending passengers at the lower terminal floor are given little opportunity to board the elevator car A. It is desirable under these circumstances to discourage such improper boarding of an elevator car which is not selected as the next elevator car to leave the lower terminal floor.

If on its next approach to the lower terminal landing the elevator car A has three passengers to be discharged, the switch PL is closed. As the elevator car A reaches thelower terminal floor, the make contacts L3 close to complete the following circuit:

L-l-, M5, PLl, R3, CA2, L3, 81, L

Consequently the capacitor CA2 charges.

As the elevator car A stops at the lower terminal the elevator car door opens in the manner previously described and the two sets of make contacts D01 and M both open to initiate a timing out operation of the noninterference relay. However, the time delay of this relay now is determined by two circuits, one including the resistor R2 and the capacitor CA1 and one including the resistor R3 and the capacitor CA2. For present purposes it will be assumed that the non-interference relay 741T now requires four seconds to drop out. This provides ample time for the discharge of the three passengers at the lower terminal floor. if desired the switch P111 may a brief time delay in drop out.

For the next condition, let it be assumed that the elevator car A is approaching the elevator terminal floor with a full load of passengers to be discharged. Under such circumstances, the switch P111 is closed and the contacts PLZ-ll also are closed. As the elevator car A nears the lower terminal floor, the make contacts L3 close to establish a charging circuit for the capacitor CA2. Since the contacts PLZ-l also are closed, a charging circui-t simultaneously is established for the capacitorCAli.

When the elevator car door opens the non-interference relay 7% starts to time out, however, the drop out time of the relay now is determined by three parallel ircuits, one including the capacitor CA1, a second circuit including the capacitor CA2 and a third circuit including the capacitor CA3. For illustrative purposes it Will be assumed that the non-interference time now is of the order of five seconds. This time interval is sufficient to permit discharge oft e full lea-dot passengers.

Because of the adjustable non-interference time ample, time is given to discharge a full load of passengers Without keeping the elevator car door open unnecessarily long when only a small number of passengers are to be discharged.

in some cases it is desirable to vary the non interference time only for a selected car or certain selected cars. For example, the non-interference time may be increased for an elevator car which is selected to be the next car to leave a terminal floor. Such a variation woud be desirable for example in a system of the type illustrated in the Carney et al. Patent 2,172,187 or in a system of the type disclosed in the Keiper et Patent 2,597,586.

The construction and operation of :an elevator system wherein the non-interference time is varied .for an elevator car selected as the next car to leave a terminal floor may be illustrated adequately by assuming that the circuits in the rectangles RE and BRE :of Fig. 2 .are replaced by the circuits in the rectangles REA and BREA shown in Fig. 5. Inasmuch as the non-interference relay 7.0T, the make contact D01, the make contacts M5, the resistor R2 and the capacitor CA1 are employed in the circuits of Fig. 2 and Fig. 5, the operation of these components in Figv 5 will be understood from the foregoing discussion. The time delay in drop out of the clay 70T in Fig. 5 is increased under certain conditions by connecting a capacitor CA3 in parallel with the capacitor CA1. Thus if the elevator car A is selected as the next elevator car :to leave the .lower terminal floor, the make contact N5 of the loading relay ,N close to connect thecapacitor CA3 in parallel with the capacitor CA1. The resulting increase in the time interval measured by the non-interference relay 70T makes it certain that the door of the elevator car A will be maintained open at least for a substantial time interval. This .assures adequate time for loading the elevator .car Aprior toits departure from the'lower terni-inalfloor.

The capacitor CA3 in Fig. 5 also is connected across the capacitor CA1 through make, contacts 70X2 when the elevator car A reaches the lower terminal floor with a substantial number of passengers to be discharged. Thus if the elevator car A is fully loaded, the make contacts PL2-1 in Fig. 5 are closed. As the elevator car A reaches the lower terminal floor, the make contacts L4 close to complete with the contacts PL2-1 and 70T4 an energizing circuit for the auxiliary relay 70X. This relay closes its make contacts 70X1 to establish a holding circuit around the contacts PL2-1. In addition, the auxiliary load relay 70X closes its make contacts 70X2 for the purpose of connecting the capacitors CA1 and CA3 in parallel. Consequently, a substantial non-interference time is provided to permit discharge of the passengers.

If it is desired to increase the non-interference time only for an elevator car which is selected to be the next car to leave the lower terminal floor the circuits in the rectangles RE and BRE of Fig. 2 may be replaced by the circuits shown in the rectangles REB and BREB in Fig. 6. Inasmuch as the components D01, 70T, M5, R2 and CA1 appear in Figs. 2 and 5, the operation of these components will be understood clearly from the foregoing discussion.

When the make contacts N5 in Fig. 6 close, as a result of pickup of the loading relay N, the capacitor CA3 and the resistor R4 are connected in parallel with the resistor R2 and the capacitor CA1. The effect of such connection is to increase the time delay in drop out of the non-interference relay '70T. Consequently with the circuits of Fig. 6 employed an elevator car selected as the next car to leave the lower terminal floors is provided with an increased non-interference time.

Although the invention has been described with reference to certain particular embodiments thereof, numerous modifications falling within the spirit and scope thereof are possible. Consequently, the particular embodiments herein discussed are to be construed in an illustrative rather than in a limiting sense.

We claim as our invention:

1. In an elevator system, a structure having a pair of terminal landings and a plurality of intermediate landings, an elevator car having a door, door-operating means for opening and closing the door, means mounting the elevator car for movement relative to the structure to serve said landings, motive means for moving the ele vator car, and control means cooperating with the motive means for controlling operation of the elevator car, said control means comprising means for stopping the elevator car at a selected landing and initiating a door-opening operation of said door operating means, initiating means responsive to the expiration of a substantial time followingthe stopping of the elevator car at said selected landing for initiating a door-closing operation of the door-operating means, :and load-responsive means responsive to the load in said elevator car for varying the magnitude of said substantial time.

2. In an elevator system, a structure having a pair of terminal landings and .a plurality of intermediate landings, an elevator car having a door, door-operating means for opening and closing the door, means mounting the elevator :car for movement relative to the structure to serve said landings, motive means for moving the elevator car, and control means cooperating with the motive means tor controlling operation of the elevator car, said control means comprising means for stopping the elevator car at a selected landing, door-control circuits for .controlling the operation of the door-operating means, and loadnesponsive means responsive to the load in the elevator car for modifying the door-control circuits.

3. an elevator system, a structure having a pair of terminal landings and a plurality of intermediate landings, an elevator car having a door, door-operating means for opening and closing the door, means mounting the elevator .car for movement relative .to the structure to serve said landings motive means for moving the elevator car, and control means cooperating with the motive means for controlling operation of the elevator car, said control means comprising means for stopping the elevator car at a selected landing and initiating a door-opening operation of said door-operating means, initiating means responsive to the expiration of a substantial time following the stopping of the elevator car at said selected landing for initiating a door-closing operation of the door-operating means, and load-responsive for providing a first value of said substantial time for a first value of load in said elevator car as it stops and for providing a second value of said substantial time smaller than the first value of the substantial time in response to the presence of a second value of load in said elevator car smaller than the first value of the load as the elevator car stops.

4. In an elevator system, a structure having a pair of terminal landings and a plurality of intermediate landings, an elevator car having a door, door-operating means for opening and closing the door, means mounting the elevator car for movement relative to the structure to serve said landings, motive means for moving the elevator car, and control means cooperating with the motive means for controlling operation of the elevator car, said control means comprising means for stopping the elevator car at a selected landing and initiating a door-opening operation of said door-operating means if a passenger is to be discharged at such landing, initiating means responsive to the expiration of a substantial time following the stopping of the elevator car and opening of the door at said selected landing for initiating a door-closing operation of the door-operating means, dispatching means for assigning the elevator car to leave the selected landing and for initiating an opening operation of the door opening means to permit loading of the elevator car, and load responsive means for providing a magnitude of said substantial time which is larger for a large value than for a small value of load in the elevator car as it reaches said landing.

5. In an elevator system, a structure having a pair of terminal landings and a plurality of intermediate landings, an elevator car having a door, door-operating means for opening and closing the door, means mounting the elevator car for movement relative to the structure to serve said landings, motive means for moving the elevator car, and control means cooperating with the motive means for controlling operation of the elevator car, said control means comprising means for stopping the elevator car at a selected landing and initiating a dooropening operation of said door-operating means, initiating means responsive to the expiration of a substantial time following the stopping of the elevator car and opening of the door at said selected landing for initiating a door-closing operation of the door-operating means, dispatching means for assigning the elevator car to leave the selected landing and for initiating an opening operation of the door opening means to permit loading, and means responsive to such assignment by said dispatching means for increasing the value of said substantial time to which the initiating means responds.

6. In an elevator system, a structure having a pair of terminal landings and a plurality of intermediate landings, a plurality of elevator cars each having a passage through which an object may pass between the exterior and interior of the car, means mounting each of the elevator cars for movement relative to the structure to serve the landings, motive means for moving each of the elevator cars, and control means cooperating with the motive means for controlling operation of each of the elevator cars, said control means comprising means for stopping any of the elevator cars at a selected landing, timing means for each of the elevator cars for measuring a first time interval and a second time interval substantially shorter than the first time interval, start-initiating means responsive to expiration of one of said time intervals measured by the timing means following the stopping of any of the elevator cars at the selected landing for initiating a starting operation of the stopped elevator car, and means responsive to load in any of the elevator cars stopping at the selected landing for transferring the associated start-initiating means from control by one of said time intervals to control by the other of said time intervals.

7. In an elevator system, a structure having a pair of terminal landings and a plurality of intermediate landings, a plurality of elevator cars each having a passage through which an object may pass between the exterior and interior of the car, each of the cars having a door and door-operating means for opening and closing the door, means mounting each of the elevator cars for movement relative to the structure to serve the landings, motive means for moving each of the elevator cars, and control means cooperating with the motive means for controlling operation of each of the elevator cars, said control means comprising means for stopping any of the elevator cars at a selected landing and initiating a door-opening operation of the door-operating means of the stopping elevator car to permit load transfer at the selected landing, timing means for each of the elevator cars for measuring a first time interval and a second time interval substantially shorter than the first time interval, door-control means responsive to expiration of one of said time intervals measured by the timing means following the stopping of any of the elevator cars at the selected landing and a door opening operation of the door of the stopping elevator car for initiating a door closing operation of the door operating means, and transfer means responsive to load in the stopping elevator car for transferring the associated door-control means from control by one of said time intervals to control by the other of said time intervals.

8. An elevator system as claimed in claim 7 wherein presence of a load in excess of a predetermined value in the stopping elevator car transfers the associated door control means from control by the shorter of the time intervals to control by the longer of the time intervals.

9 An elevator system as claimed in claim 7 in combination with dispatching means for selecting the 'next elevator car to leave the selected landing, and means responsive to selection of an elevator car having a closed door to leave the landing for initiating a door-opening operation of the elevator car, said door-control means including means effective after said last-named door-opening operation for thereafter closing the last-named door and initiating a starting operation of the associated elevator car.

10. In an elevator system, a structure having a pair of terminal landings and a plurality of intermediate landings, a plurality of elevator cars each having a passage through which an object may pass between the exterior and interior of the car, each of the cars having a door and door-operating means for opening and closing the door, means mounting each of the elevator cars for movement relative to the structure to serve the landings, motive means for moving each of the elevator cars, and control means cooperating with the motive means for controlling operation of each of the elevator cars, said control means comprising means for stopping any of the elevator cars at a selected landing and initiating a door-opening operation of the door-operating means of the stopping elevator car to permit load transfer at the selected landing, timing means for each of the elevator cars for measuring a first time interval and a second time interval substantially shorter than the first time interval, door-control means for maintaining open the door of a stopped elevator car for one of the intervals determined by said timing means for the associated car, dispatching means for selecting the next elevator car to leave the selected floor, and transfer means responsive to selection of such next elevator car for transferring the door-control means of such next elevator car from control by one of the intervals to control by the other of said intervals.

11. In an elevator system, a structure having a pair of terminal landings and a plurality of intermediate landings, a plurality of elevator cars each having a passage through which an object may pass between the exterior and interior of the car, each of the cars having a door and dooroperating means for opening and closing the door, means mounting each of the elevator cars for movement relative to the structure to serve the landings, motive means for moving each of the elevator cars, and control means cooperating with the motive means for controlling operation of each of the elevator cars, said control means comprising means for stopping any of the elevator cars at a selected landing and initiating a door-opening operation of the door-operating means of the stopping elevator car to permit load transfer at the selected landing, timing means for each of the elevator cars for measuring a first time interval and a second time interval substantially shorter than the first time interval, door-control means for maintaining open the door of a stopped elevator car for the shorter one of the intervals determined by said timing means for the associated elevator car, dispatching means for selecting the next elevator car to leave the selected floor, transfer means responsive to selection of such next elevator car for conditioning the door-control means of such next elevator car to maintain open the door of such next elevator car for the longer of said intervals, and means responsive to closure of the door of such next elevator car for starting said next elevator car.

References Cited in the file of this patent UNITED STATES PATENTS 2,634,827 Suozzo Apr. 14, 1953 

